The present invention generally relates to optical disc recording apparatuses, and more particularly to an optical disc recording apparatus which carries out a recording by variably controlling a quantity of light of a recording light beam depending on a radial position of the recording light beam on an optical disc.
Conventionally, in an optical disc recording apparatus which records an information signal on an optical disc which rotates at a constant rotation frequency by use of a recording light beam, it is known that the information signal cannot be recorded with a satisfactory signal-to-noise (S/N) ratio unless the light quantity is increased as a radial position of the recording light beam on the disc approaches an outer periphery thereof because a relative linear velocity between the disc and the recording light beam increases as the radial position of the recording light beam on the disc approaches the outer periphery from an inner periphery. For example, a Japanese Laid-Open Patent Application No. 50-92702 discusses this problem although an electron beam is used rather than a light beam.
However, in the case where a semiconductor laser (laser diode) is used as a light generating source for the recording light beam, problems occur since the semiconductor laser is easily affected by the ambient temperature. For example, even when a driving current is kept constant, an output of the semiconductor laser obtained with the ambient temperature of 50.degree. C. is approximately 1/2 an output of the semiconductor laser obtained with the ambient temperature of 0.degree. C. Further, an output characteristic of the light generating source also changes with age. Accordingly, there is a problem in that it is impossible to record the information signal with a satisfactory S/N ratio by simply controlling the quantity of light of the recording light beam depending on the radial position of the recording light beam on the disc.